Variable-speed mechanism.



No, sso. ?ATBNTEB MAR. 26E 1907.

G. M. SENGUR,

VARIABLE SPEED MEUHANsR/,

APPLYCATION 'FILED MAILS i909.

Z SHEETS-SHEET l.

NoL 848,606. PATENTED MAR. 26, 1907. G, M. SFENGER,

VARIABLE SPEED MEGHAMSM.

APPLICATION Hmm MAR. 8. 1906.

2 SHEETS-SHEET 2.

CHRISTOPHERM. SPENCER, or winnson, CONNECTICUT, AssreNCR To THE yUNIVERSAL MACHINE SCREW COVIPANY OF HARTFORD, CONN ECTICUT,`

A CORPORATlON OF CONNECTTCUT.

VARIABLE-SPEEE MEGHANiSM,

Specification of Letters Patent.

Patented March 26, 1907.

Original application filed May 4, 1904, Serial No. 206,277. Divided andthis application filed March S, 1906. Serial No. 304,839.

To VLZZ w/wm'zlt may Concern:

/y Beit known that I, CHRISTOPHER M. SPEN- CER, a citizen of the UnitedStates, residing at Windsor, in the county of Hartford and 5 State ofConnecticut, have invented a new and luseful V ariableSpeed Mechanism,of which the following is a specification.v

This invention relates to a mechanism which is particularly designed forrotating the cam-shaft of an automatic multiple-spindlescreW-machine`such, for instance, as is shown and described in myapplication for patent for automatic screw-machine, iiled May 4, 1904,SerialNo. 206,277; but'it is also applicable to other' machines in whichit is desirable to at intervals change the speed of the driving-shaft.

The object of the invention is to produce a very simple mechanism bymeans of which .the speed of a shaft-such', for instance, as theCain-shaft of a-screw-machine-can be instantly greatly increased, aswhen the cutl ting-tools of such a machine are being drawn away fromand, fed up to the work, without necessita-ting the speeding up ordriving rapidly of the gears which are employed to reduce the speed ofthe shaft, as when the tools are operating, thus saving power, reducingWear, and enabling the change to be acconi- .plished quickly, andconsequently allowing the speed of the machine to be increased.

lt is very desirable in order to economize time to withdraw the toolsfrom and advance them up to the stock rapidly and then to in- 3 5sta'ntly slow down while the tools are cutting. This is accomplishedwith this n'ieehanism by automatically sliding the belt by a beltshifteroperated by 'means of cams on the cam-shaft onto a pulley which drivesthe worm-shaft directly at a rapid rate and then 'at the proper timesliding the beit bach onto a pulley which drives the Worm-shaftindirectly through suitable gearing, the gearing being so connected withthe shaft that it does not have torun as fast as the shaft when theJshaft is driven directly.

Figure 1 ofthe accompanying drawings shows a front elevation of aportion of a screw-machine provided with a variable- 5o speed mechanismwhich embodies the invention. Fig. 2 shows anfelevation of the pulleys,belt-shifter, and shifter-operating cams. Fig. 3 shows a horizontalsection, on larger 'shaft is supported byv suitable bearings arscale,through the pulleys and gearing.. Fig.` 4 shows a face view of thegears.

The wormshaft 1 has a worin 2, which meshes with aworm-wheel Sen thecam-shaft 4, which bears the cams which feed the tools toward and fromthe stocli. The worm- 6o ranged in the bed of the machine in a coinmonmanner. On the front end ofthe wormshajft is the high-speed pulley 5.This pulley is keyed to or otherwise iiXed tight to the shaft, so thatthe rotation of the pulley will rotate the shaft and the worm directly.Loose on the shaft inside of the iixed pulley is the low-speed pulley 6.This pulley turns freely on the shaft and has a long hub 7, to which agear S is removably attached by devel-pins 9. This gear is fast ined bypins in this manner so that it may be easily removed and one ofdilferent size substituted, if desired.

Turning loosely on the hub of the lowspeed pulley is the loose pulleyl0. l/Vlien it is desired to have the mechanism remain stationary,v thebelt is slipped upon this loose pulley.

lurning loosely on the worin-shaft is a gear 1l, which carries a pawll2, and keyed or otherwise secured to the shaft adjacent to thepawl-gear is a ratchet 125. A spring 14 is arranged to hold the pawlagainst t-he surface of the ratphet which is keyed to the shaft.

On a stud that projects from the frame of the machine are gears 15 and16. These gears turn loosely on thc stud and are held together so as toact as one part by pins, so that they may be easily separated forchanging their relative diameters if a different speed is desired.

On the end of the cam-shaft is a disk 17, and clamped on the peripheryof this dish are two cam-blocks 18 and 19.' llinged tothe frame adjacentto this dish is a lever 20, the lower end of vwhich bears a roll 2l,that is adapted to be engaged by the cam-blocks, and the upper end ofwhich bears a forli` 22., which is adapted to embrace the driving-belt.Extending from the lever is a handie 23.

When the f am 15 engages the roll 2l, the `lever oscill tted so that the.fork guides the belt onto thel lowspeed pullei7 When the IOL eem i9engages the roll "il, the lever isso oseillateil that the i'ork guidesthe belt onto, the high-speed pulley When it is.. desirable to. have themechanism stand idle, the leverI may he oseillated hy hallal so that the'fork will guide the lever onto the loose pulley. l

when the heit is on the loose pulley, the ii'eil -siialt remains idle.When the holt is ori the loi/.speell pulley, the shaft is driven tirough the gears arial the pawl and ratchet. in this ease the lowspeeilpulley through the gear which is piimeil to its huh rotates the gearsthat are pinned together on the stud, the inner ot which rotates theloose freer hearing the pearl, which engages the retehet 'that is keyedto the shaft.

Villino the holt is on theI high-.speed pulley, the shalt llriyoiidirectly, for that pulley is fastened to the shaft. lo this ease whenthe shalt first eoiiimeices torotate at the hi rh 'rete ol speed atwhich the pulley runs tie ratchet runs away from and rides under thepawl, so that it is hot necessary to piel( up and drive the gearing etthe high speed.

fin the meehanism which is illustratedthe pulleys are designed to hedriven at thel same rate of' speed and the gears are proportioned sothat the .li'llerenee in the rotations of the worrirshait when driven bythe high-speed and the lorvspeed pulleys is as nine to one, itlow-speeil gears were positively eoriiiectefl with the shaft, it wouldhe necessary alter the helt was shifted onto the high-s eed pulleybefore the high speed, could lie rea ized sieeoe but' with theiatclietaml-pawl Connection :whielivis showri'this is 'imrieeessar 'forthe `retchetruiis away' from the 'pawhso'tliat the inertie of the gearsOilers no resistanee tothe rotation of the worm-shaft at high speed. @naeeolint' of this the speed of the iriaehine can he increased. The wearon the parts is much reduced, and more accurate work, een be donebecause of the less Wear and because the change ol' speed can beaccomplished quickly.

The invention elaimed-is'- A variehle-speed mechanism having 4awormehatt, ya pulley fixed to the Wormshalt, a pulley adieeent'theretoand loose on the worimsheit, im idle pulley free on the hoh of the loosepulley, a gear ori the Wormsha'lt adjacent to and oomieoted with the hubof the loose pulley, a gear loose ori the worm shalt, two gears fastenedtogether on a parellel shaft, one of said gears meshing with the gearthy-at is oomieetedjvith thehuh of the loose pulley and the other ofsaid gears meshingy with the gear that is loose oli/the worm-shaft, apawl carried' by the gear that is loose on the worm-shaft, and e ratchetfixed to the worm-shaft and engaged by the pawl, suhstautially asspecified.

( l'iitlSTPilER M. SPENCER.

l/Viti'iesses l'lAimY it. WILLIAMS, Emmi'. elbows'.

l to get all of the gears rotatiiig at high speed;

